The present invention relates to a novel method for the preparation of a heat-resistant silicon-containing polymer or, more particularly, to an efficient method for the preparation of a silicon-containing polymer having a structure of organic polymers bonded through siloxane linkages and exhibiting excellent heat resistance to be useful as a constituent of coating compositions, material of structural members for high-temperature service, and so on.
An organic-inorganic hybrid polymer having a structure of organic polymers bonded through siloxane linkages, sometimes called an "ormocer", "ormosil" or "ceramer", has excellent properties including high mechanical strength, high heat resistance, flame retardancy, light-fastness and so on so that polymers of this type are promising and under extensive development works as a constituent of coating compositions, material of structural members for high-temperature service and the like. The properties of these organic-inorganic hybrid polymers are intermediate of organic polymers, i.e. plastic resins, and inorganic materials, i.e. glass and ceramics, so that the application fields thereof are expected to cover those in which satisfactory performance can be exhibited by none of the conventional organic materials and inorganic materials as well as mere combinations thereof as is the subject matter in a large number of reports and reviews.
One of the prior art methods for the preparation of a polymer having a structure of organic polymers bonded through siloxane linkages is the so-called sol-gel method in which the starting materials are an organic polymer having alkoxysilyl groups and an alkoxysilane compound to be subjected to a cohydrolysis-cocondensation reaction. This method, however, has problems and disadvantages and cannot be an industrially practicable method because the process of this method includes a number of steps and it is unavoidable in the steps of condensation reaction and removal of the solvent, alcohol as the hydrolysis product and excess of water that cracks are formed in the body under processing.